Coil-type zipper stringer

ABSTRACT

A coil-type zipper stringer is disclosed which a home sewer is enabled to produce directly on a material using a family-type zigzag sewing machine. The material is positioned under and to one side of a stuffer cord. A zipper coil is positioned in parallel contact with the other side of the stuffer cord so that the total throw of the zigzag sewing machine needle during one stitch sequence encompasses from the material on the one side of the stuffer cord to an inside loop of the zipper coil on the other side of the stuffer cord, whereby the zigzag stitching locks the material, the stuffer cord and the zipper coil together to form a zipper stringer, wherein the stitch crossover occurs on a bottom portion of the zipper stringer.

0 United States Patent [n13,600,767

31 Inventors Roy M. Cowdny 3,l47,529 9/1964 Wilcken ..24/205.l6 C UX Lake Hlawatln; 3,249,976 5/1966 Burbank ..24/205.l C UX Robert B. Branch, Wayne, N..l.; Anne C. 3,412,438 ll/l968 Sim 24/205. l 3 C UX Cllpp,Sller City, N.C. 3,474,505 10/1969 Glindmeyer. ..i24/205.l6C UX I 1 I I PP No 833,972 FOREIGN PATENTS |i2l Filed June [7, [969 '4 Pacmed M814, 1971 1,555,254 l2/l968 France 24/205. [6C

I 71 Assignee The Slnger Company Primary Examiner- Bernard A Gelak New York, NX. Attorneys-Marshall J. Breen, Chester A. Williams and l 4] COIL-TYPE ZIPPER STRINGER 56] References Cited UNITED STATES PATENTS 2,858,592 11/1958 Schwartz. i.24/205.l3 C UX 3,135,036 6/1964 Burbank .i24/205.lCUX

= lilll Robert E. Smith ABSTRACT: A coil-type zipper stringer is disclosed which a home sewer is enabled to produce directly on a material using a family-type zigzag sewing machine, The material is positioned under and to one side ofa stuffer cord. A zipper coil is positioned in parallel contact with the other side of the stuffer cord so that the total throw of the zigzag sewing machine needle during one stitch sequence encompasses from the material on the one side of the stuller cord to an inside loop of the zipper coil on the other side of the stuffer cord, whereby the zigzag stitching locks the material, the stuffer cord and the zipper coil together to form a zipper stringer, wherein the stitch crossover occurs on a bottom portion of the zipper stringer fllillllF- Patented Aug. 24, 1971 INVhAlORS 3 Roy M. Cowdrey Robert B. Brauch Anne C. Clapp Y M Q. T

Q Q w Q Q WITNESS COIL-TYPE ZIPPER STRINGER BACKGROUND OF THE INVENTION Many different methods have been proposed heretofore for securing the fastener elements of a zipper to a material of a tape or fabric. The usual procedure includes a first step of securing a stuffer cord to the material, and a second step in which the fastener is attached.

In the manufacture of zippers of the type including metal or plastic teeth, the stutfer cord is either sewn to the edge of the material or folded in a portion of the material wherein the fold is stitched through to secure the cord and material together. The material with the stuffer cord thereon is then fed into a machine in which the fastener teeth are made and/or crimped or clinched on the cord and a portion of the material.

In the manufacture of the so-called spiral or coil-type of fastener, the best practice has been to use a special type of tape which is woven in such a manner that picks are dropped between the edges of the tape to give a ladderlike formation through which the coil strip is slipped to secure it in position. The tape is then sewn to a fabric in the usual manner.

The coiled strip has been sewn directly to tape, where this has been done by using either an overedge sewing machine, as disclosed in US. Pat. No. 2,858,592 or a two-needle sewing machine as disclosed in U.S. Pat. No. 3,249,976, wherein neither of the above sewing machines is considered to be a family-type sewing machine. Attempts have been made to sew the coiled strip directly to the tape using a single needle straight stitching sewing machine, but have not proved to be very successful because the convolutions of the coiled strip stretch and contract so that spacing of the convolutions may not be exact. As a result, the needle may not enter between each convolution and make a secure tie with the tape. Moreover, the needle may actually strike the coiled strip and break either the strip or the needle.

SUMMARY OF THE INVENTION This invention relates to a coil-type zipper stringer of a slide fastener and to the method of makingthe stringer, wherein the zipper coil is continuously applied to the material of a tape or a fabric of an article or garment per se, using a family-type zigzag sewing machine. The material is positioned under and to one side of a stufler cord. The zipper coil is positioned in parallel contact with the other side of the stuffer cord. The total throw of the zigzag sewing machine needle during one stitch sequence encompasses the stuffer cord, thereby locking the material to the stuffer cord on the one side and locking an inside loop of the zipper coil to the stuffer cord on the other side to form the zipper stringer, which may be of any desired length.

One object of this invention is to provide a zipper stringer of a slide fastener which would be easily sewn directly to a fabric of an article or garment. This invention reduces the number of steps necessary to sew a zipper, wherein the tape, to which the fastener elements are usually secured, is eliminated and therefore no basting operation is necessary to position the tape on the fabric. The left and right coils of this invention are applied separately allowing the sewer to stitch on a single garment part at one time, thereby reducing the amount of manipulating of the garment which normally takes place at the sewing machine. Fabric patterns can be made to match perfectly at the placket area by using this invention, which reduces the frustrations many sewers have when an entire zipper has to be ripped out when the garment parts and fabric pattern do not match properly. This invention is more acceptable when using sheer fabrics than a conventional zipper with a tape, where elimination of the tape reduces the bulk and shadowed seam appearance. Also, this invention will enable the home sewer complete versatility in creating a garment closure, where no longer will the home sewer be restricted by standard zipper availabilitv as to len ths. colors and textures.

Another object of this invention is to provide a zipper stringer of a slide fastener which would make it easier to control shrinkage which is a major cause of puckering. This type of closure sewn directly to a fabric reduces the differential shrinkage due to unlike material mating encountered when using the common zipper tapes.

Still another object of this invention is to provide a zipper stringer which would effectually permit curved, spherical and angled seam designs. The zipper of this invention, without a concealing placket, could be used as a decorative item, wherein colored cord or tape trims could be used as a design feature. Also, panel construction of garments with many separate parts connected by zippers becomes possible for the home sewer through use of this invention, wherein this has added advantages in designing childerns clothing and maternity wear where alterations for growth can be made by zipping in new sections.

The above and other objects, features, and advantages of the present invention will be apparent from the following description, appended claims and annexed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of the present invention, reference may be had to the accompanying drawings in which:

FIG. 1 represents a fragmentary perspective view taken in the needle region of a zigzag sewing machine, such view showing a presser foot in an operative position for sewing a coiltype zipper stringer according to the present invention;

FIG. 2 represents a fragmentary perspective view showing the action of a zigzag sewing machine needle in securing the zipper coil, the stuffer cord and the material together to form the coil-type zipper stringer of this invention;

FIG. 3 represents a fragmentary plan view of the section of the coil-type zipper stringer of this invention illustrated in FIG. 2, but viewed from the reverse side.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, FIG. 1 illustrates a fragment of a bracket arm 11 of a zigzag sewing machine frame including a bushing 12 secured in the bracket arm 11 and a presser bar 13 endwise slideable in the bushing 12. The presser bar 13, as is conventional, may be biased downwardly by a spring (not shown) and furthermore, the presser bar 13 may be raised at will by the sewing machine operator by means of a presser lifting lever (not shown) carried on the bracket arm 11. Also endwise reciprocable in the bracket arm 11 is a needle bar 14 carrying a needle 15 which holds a thread T for the formation of stitches. The sewing machine frame includes a work-supporting bed I6 beneath the bracket arm 11. Carried on the bed 16 are a bed slide 17 and a throat plate 18 which is formed with slots (not shown) through which a feed dog (not shown) of a conventional zigzag sewing machine feed mechanism is operative. Carried on the presser bar 13 and urged downwardly against the bed slide 17 and the throat plate 18 is the presser foot 20. The presser foot 20 comprises a shank 21 adaptable for connection to the presser bar 13, and a soleplate 22 which may be exchangeably accommodated on the shank 21.

The presser foot shank 21 is set forth in a copending application, Snap-on Presser Foot Shank, Ser. No. 752,663, assigned to the assignee of this invention. The shank 21 is formed at the top with a presser bar accommodating seat and is secured to the presser bar 13 by means of a shouldered clamp screw 25 which is threaded into the presser bar 13. Depending from the presser bar accommodating seat is a blade having a narrow elongated slot 26 extending substantially lengthwise of the presser foot shank blade. The slot 26 joins a downwardly open socket (not shown) formed in the bottom of the blade.

The presser foot soleplate 22 is set forth in a copending application, Presser Foot for Sewing a Coil-Type Zipper Strinoer. Ser Nn R77 R66 films Mnr on I060 Mata-ma M the assignee of this invention. The soleplate 22 is formed with upstanding ears 23 spaced apart a distance substantially equal to the thickness of the presser foot shank 21. Carried by the ears 23 and extending transversely therebetween is a cylindrical pivot pin 24 which is positioned and held in the open socket formed in the bottom of the presser foot shank blade.

Two parallel guide apertures 34, 35 are formed in a front edge of a raised forward portion 33 and extend in open communication with a needle aperture 31. The guide aperture 34, usually the smaller of the two, is formed to align with the center position of the needle 15. A slot 32 extends from the needle aperture 31 to an edge of the soleplate 22 to allow the thread T to pass therethrough when a material or a fabric F is desired to be removed from or returned under the presser foot 20 during the sewing of a zipper stringer Z.

A toe portion 36 is angled down from the needle aperture 31 to the front edge of the soleplate 22 so that the toe portion 36, which pivots about the axis of pin 24, is in constant contact with the bed slide 17 during the entire feeding cycle. Portion 37 connects the raised portion 33 to the toe portion 36. A vertical side surface 38 of the soleplate 22 extends downwardly from portion 33, along a wall or portion 37 and an edge of toe portion 36 to the bottom surface of toe portion 36 and is substantially in line with the guide aperture 34.

A clearance groove (not shown) is formed in the bottom surface of the soleplate 22 extending from the needle aperture 31 through the rear portion 40, to allow passage of the sewn zipper stringer Z. The rear portion 40 is turned up in the convention manner.

The fabric F is positioned under the presser foot 20, as shown in FIG. I, with an edge of the fabric F, which may be folded as shown in FIG. 2, positioned against the vertical surface 38. Surface 38 guides the edge of the fabric F under the raised portion 33 of the soleplate 22 to the needle aperture 31, where the edge of the fabric F is approximately aligned with the center needle position with the bulk of the fabric F to the left thereof.

Aperture 34 of the raised portion 33 of the soleplate 22 receives a stuffer cord S and guides the stuffer cord S under the soleplate 22 to the needle aperture 31. At the needle aperture 31, the stuffer cord S is positioned above an in contact with the fabric F, as shown in FIG. 2, and in alignment with the center needle position. Aperture 35, usually the larger of the two guide apertures of the raised portion 33, receives a zipper coil C and guides the zipper coil C in parallel contact with the stutter cord S under the soleplate 22 to the needle aperture 31. At the needle aperture 31, the zipper coil C is positioned to the right side of the stuffer cord S, as shown in FIG. 2, being separated from the fabric F by the stufi'er cord S.

Each coil or loop of the zipper coil C is of generally oval shape in cross section having an interlockable head H which engages similar interlockable heads of a mating zipper coil when joined by a conventional slider. The interlockable heads H are aligned on one side of the zipper coil C. The zipper coil C, when placed in aperture 35, is positioned with the interlockable heads H on the right side, as shown in FIG. 2, away from the stuifer cord S.

Adjustment is made with the stitch length selector (not shown) of the zigzag sewing machine such that the spacing from needle hole 1 to needle hole 2, shown in FIGS. 2 and 3, is approximately equal to the spacing between each loop of the zipper coil C so that a stitch will be formed between each loop. Adjustment is also made with the stitch width selector (not shown) of the zigzag sewing machine such that the total throw of the needle during one stitch sequence, as indicated in FIG. 2, encompasses from the fabric F on one side of the stuffer cord S to an inside portion of a loop of the zipper coil on the other side of the stuffer cord. It is noted that neither the stuffer cord S nor the zipper coil C is pierced by the needle 15. With the tension on the thread T adjusted to give an U'l'lbalanced stitch, as indicated on the reverse side of the zipper stringer Z shown in FIG. 3, the stitching will form a series of thread loops on an inside portion of each loop of the zipper coil C and will also form another series of thread loops which penetrates through the fabric F.

On a bottom portion of the zipper stringer Z, as shown in FIG. 3, one series of thread loops is laterally spaced from the other series of thread loops, where the bights of the thread loops of one series are diagonally spaced from the bights of the thread loops of the other series defining a zigzaglike spacing alternating from a thread loop bight of one series to an adjacent thread loop bight of the other series. The stitch crossover occurs on the bottom portion of the zipper stringer Z, adjacent to the stuffer cord S as shown in FIG. 3 where the bobbin thread B, in a zigzag manner, engages the bight of each thread loop to connect together the series of thread loops formed by the needle thread T, thereby engaging and locking together the fabric F, the stuffer cord S and the zipper coil C to form the zipper stringer Z.

The feed dog of the sewing machine moves the fabric F so that the sewn zipper stringer Z passes through the clearance groove formed in the bottom rear surface of the soleplate 22. This movement also draws the stufier cord S and the zipper coil C through the guide apertures 34, 35, respectively, to their sew positions under the soleplate 22 at the needle aperture 31. If desired, a portion of the zipper coil aperture 35 adjacent to the needle aperture 31 could be made slightly smaller than the zipper coil C to exert a slight frictional force on the next loop to be sewn, causing the spacing between the loop being sewn and the next loop to be made larger during the time of sewing, and thereby increasing the clearance for the needle 15. Obviously, the above frictional force is substantially less than the force exerted by the feed dog to draw the zipper coil C. It is noted that the zipper stringer Z could be made any desired length.

A like procedure is carried out on a matching fabric using the stuffer cord S and zipper coil C to form a mating zipper stringer for a slide fastener. The two fabrics are matched with the zipper coils of the fastener adjacent to each other. A conventional slide (not shown) is locked onto the mating zipper stringers by using metal stops, tacking or other suitable means. The fabrics are joined using the slider to interengage the heads of the zipper coils, whereby the stuffer cords of the fastener serve as guides for the slider.

Though the zipper stringer of the present invention is shown as being formed by using zigzag lock stitch comprising a needle thread and a bobbin thread, the zipper could be formed by using a single thread zigzag chain stitch. The thread of the chain stitch would form a first and a second series of thread loops on the bottom portion of the zipper stringer, similar to those formed by the thread T as shown in FIG, 3, wherein the first series of thread loops would engage an inside portion of each loop of the zipper coil and the second series of thread loops would engage the fabric. However, with the absence of the bobbin thread I3, the bight of each loop of each series of thread loops formed by the chain stitching would be obliquely extended to engage an adjacent thread loop of the respective other series of thread loops, as is conventional in a single thread chain stitch, to connect together in a zigzag manner the series of thread loops of the chain stitch, thereby locking together the fabric, the staffer cord and the zipper coil to form the zipper stringer.

Numerous other alterations of the structure and method herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention.

Having thus set forth the nature of the invention, what is claimed herein is:

l. A zipper stringer comprising a zipper coil having continuous loops, each of said loops having an interlockable head, said interlockable heads being aligned to form a row on one lengthwise side of said zipper coil, a material having an edge extending adjacent to an opposite lengthwise side of said ziooer coil with said rnw nf intprlnrlrahln hear: imam. saw--4 ing from the same side of said zipper coil and material, and a single bobbin thread alternately interconnecting said first series and said second series of thread loops at the opposite side of said zipper coil and material with said bobbin thread extending directly from a loop of one series to a loop of the other series thereby locking said zipper coil to said material to form said zipper stringer, whereby said zipper stringer may be made any desired length. 

1. A zipper stringer comprising a zipper coil having continuous loops, each of said loops having an interlockable head, said interlockable heads being aligned to form a row on one lengthwise side of said zipper coil, a material having an edge extending adjacent to an opposite lengthwise side of said zipper coil with said row of interlockable heads being spaced from said material, and lockstitch zigzag stitching means attaching said zipper coil to said material comprising a single needle thread defining a first and second series of thread loops laterally offset alternately from each other in the direction of stitch formation, said first series of thread loops engaging an inside portion of each zipper coil loop wherein the inside portion of each coil loop is engaged by a single loop of said first series, said second series of thread loops engaging said material, each of said first and second series of thread loops extending from the same side of said zipper coil and material, and a single bobbin thread alternately interconnecting said first series and said second series of thread loops at the opposite side of said zipper coil and material with said bobbin thread extending directly from a loop of one series to a loop of the other series thereby locking said zipper coil to said material to form said zipper stringer, whereby said zipper stringer may be made any desired length. 